Discus Launched (radio controlled) Gliders

An introduction to DLG aircraft and competition.

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what is Thermal?


DLG Intro

It is a wonderful feeling to watch a glider thrown from your own hand circling like a hawk, rising hundreds of feet.

A radio controlled (R/C) Discus-launched Glider (DLG) is thrown by the pilot from a wingtip to heights of up to 260 feet. The pilot then controls it, searching for lift in the air – namely, thermals (rising warm air) and object-induced lift (wind hitting a hill and going upwards). There are contests (competitions) that test pilots’ skill in finding this lift, strategies, and launch technique. In contest form, this type of flying is FAI class F3K. For more information on R/C aircraft in general, please see https://www.modelaircraft.org/

Why is this so fun? What is the appeal of no engine? Well, it turns flying an R/C aircraft into A game of skill and chance, not only from simply controlling the glider, but in learning to “read” the conditions and find lift. Plowing through the sky with a motor has its appeal, too, but does not have the same excitement of “catching a thermal”. It may be considered similar to catching a fish! Both skill and luck are required, and the anticipation of the unknown contributes to the addiction.


DLGs are most often constructed as high-performance aircraft, typically hand-built in the numbers of “dozens per year” by each manufacturer (of a few people in total size). Typical construction is carbon fiber and epoxy with special foam-cores for wings and tails. The 1.5 meter wingspan aircraft weight between 200-260 grams, typically! Not only that, but they also are able to withstand extreme forces during launch.

They are expensive to the uninitiated, with new models ranging in price from USD$680 to $1000. Luckily, most pilots new to the hobby buy a previously-loved used model for between $250-$500. The floor price rarely drops below this, so they are often resold after the addition takes hold. There are a few models cheaper than this, and while they might be suitable in some situations, it is generally much more desirable to own a contemporary composite-built glider. They fly better, are much more durable, and have better resale value.

A few bold individuals decide to create their own DLG from scratch. This is not for the faint-of-heart, but is certainly possible!


Go to a contest if you want to meet others interested in powerless flight! Your skill level doesn’t matter, and it is probably more important to chat if your experience is less.

The “F3K” style contest is organized in a number of rounds (usually 10 minutes long, each) with each round being assigned a task from the official task list. These tasks are formulated based on flight time. The flight times contribute to a pilots score or points for the round. The optimal flight times depend on the task.

For example, Task A: Last Flight is a task that scores only the last flight that a pilot makes in the 10-minute task window. If a pilot is struggling to find lift, and manages a 3:00 minute flight, he or she may decide to not launch again even if time is left (since if the next flight is shorter, it would be fewer points!).

Thus, development and execution of strategy is a large part of the appeal of flying in contests. Not only is it a game with Mother Nature (micrometeorology) but against fellow pilots!

Other Helpful Links

This community is hyper-focused on DLGs, and especially contests/competitions. While the organization of this forum is a bit poor, there is a wealth of information there. If in doubt, post a question and you’ll get some help.

Look out for keywords “DLG” attached to a model name. Popular ones include: “Snipe”, “Stream NXT”, “Vibe”, “BAMF”, “Vortex”, “CX4”, CX5”, “Falcon”, and many more..

F3K rules and task descriptions (Note, this page is old, and has been changed; Sadly the FAI organization does not easily provide these.. I’ll link to the updated rules when I find them)